Hematopoietic progenitor cells increase remarkably in the peripheral blood of children with infection

Background: Peripheral blood (PB) of children with viral infection had remarkable increase in colony-forming unit-granulocyte/ macrophage (CFU-GM)-derived colonies and clusters. The authors sought to investigate the hematopoietic changes in children with infection. Methods: The CFU-GM-derived colonies and clusters, burst-forming unit-erythroid (BFU-E)-derived colonies, and colony-forming unit-megakaryocyte (CFU-MK)-derived colonies assays and methylcellulose and/or agarose culture of PB were performed in 25 controls and 42 infected patients. Hematopoietic cell assays and cell culture of bone marrow (BM) were performed in 28 controls and 12 infected patients. Results: The PB controls had very few CFU-GM-derived colonies and clusters. The PB of infected children had many more CFU-GM-derived colonies and clusters. In addition, PB of infected children had abundant BFU-E-derived colonies and CFU-MK-derived colonies, whereas, from BM there were no statistical differences in the numbers of CFU-GM-derived colonies and clusters, BFU-E-derived colonies, and CFU-MK-derived colonies between infection group and control group. The numbers of CFU-GM-derived colonies and clusters were greater in PB of bacteria-infected patients than those in PB of non-bacteria-infected patients. Conclusions: PB of infected children had increased numbers of colonies, especially in the bacteria-infected group.